使用 startActivityForResult 从类到活动

Question

找不到一个好的答案。我有一个类(没有从主活动打开。 在那里，我想调用startActivityForResult，以了解何时在UI上执行某些操作。 如何正确操作？我将活动和上下文传递给了类。 上课：

private void init(){
Intent TestIntent = new Intent();
mActivity.startActivityForResult(TestIntent,MainActivity.TEST);
}

在主活动上：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent Data) {
super.onActivityResult(requestCode, resultCode, Data);
if (requestCode == TEST){
Toast.makeText(this, "TEST", Toast.LENGTH_SHORT).show();
}
}

Answer 1

检查一下，您必须传递具有所需类意图的代码

private void init(){
Intent TestIntent = new Intent(this,SecondClass);
startActivityForResult(TestIntent,222);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent Data) {
super.onActivityResult(requestCode, resultCode, Data);
if (requestCode == 222){
Toast.makeText(this, "TEST", Toast.LENGTH_SHORT).show();
}
}

Answer 2

您的TestIntent为空。它没有任何内容可以告诉AndroidActivity开始什么。您需要像这样创建Intent：

private void init(){
Intent TestIntent = new Intent(mActivity, ActivityToStart.class);
mActivity.startActivityForResult(TestIntent,MainActivity.TEST);
}

Answer 3

private void init(){
Intent intent = new Intent(this,another.class);
startActivityForResult(intent,requestCode);

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent Data) {
super.onActivityResult(requestCode, resultCode, Data);
if (requestCode == reruestCode){
Toast.makeText(this, "TEST", Toast.LENGTH_SHORT).show();
}
}

private void getResponse(){
setResult(RESULT_OK,new Intent());
finish();
//Use this block of code in the second class.
}